Re: [PATCH v4 3/6] drm/xe/hwmon: Expose card reactive critical power

[Riana Tauro <riana.tauro@xxxxxxxxx>]

On 9/4/2023 11:52 PM, Badal Nilawar wrote:
> Expose the card reactive critical (I1) power. I1 is exposed as
> power1_crit in microwatts (typically for client products) or as
> curr1_crit in milliamperes (typically for server).
>
> v2: Move PCODE_MBOX macro to pcode file (Riana)
> v3: s/IS_DG2/(gt_to_xe(gt)->info.platform == XE_DG2)
> v4: Fix review comments (Andi)
>
> Signed-off-by: Badal Nilawar <badal.nilawar@xxxxxxxxx>
LGTM
Reviewed-by: Riana Tauro <riana.tauro@xxxxxxxxx>
> ---
>   .../ABI/testing/sysfs-driver-intel-xe-hwmon   |  26 +++++
>   drivers/gpu/drm/xe/xe_hwmon.c                 | 105 +++++++++++++++++-
>   drivers/gpu/drm/xe/xe_pcode.h                 |   5 +
>   drivers/gpu/drm/xe/xe_pcode_api.h             |   7 ++
>   4 files changed, 142 insertions(+), 1 deletion(-)
>
> diff --git a/Documentation/ABI/testing/sysfs-driver-intel-xe-hwmon b/Documentation/ABI/testing/sysfs-driver-intel-xe-hwmon
> index da0197a29fe4..37263b09b6e4 100644
> --- a/Documentation/ABI/testing/sysfs-driver-intel-xe-hwmon
> +++ b/Documentation/ABI/testing/sysfs-driver-intel-xe-hwmon
> @@ -20,3 +20,29 @@ Description:	RO. Card default power limit (default TDP setting).
>   
>   		Only supported for particular Intel xe graphics platforms.
>   
> +What:		/sys/devices/.../hwmon/hwmon<i>/power1_crit
> +Date:		September 2023
> +KernelVersion:	6.5
> +Contact:	intel-xe@xxxxxxxxxxxxxxxxxxxxx
> +Description:	RW. Card reactive critical (I1) power limit in microwatts.
> +
> +		Card reactive critical (I1) power limit in microwatts is exposed
> +		for client products. The power controller will throttle the
> +		operating frequency if the power averaged over a window exceeds
> +		this limit.
> +
> +		Only supported for particular Intel xe graphics platforms.
> +
> +What:		/sys/devices/.../hwmon/hwmon<i>/curr1_crit
> +Date:		September 2023
> +KernelVersion:	6.5
> +Contact:	intel-xe@xxxxxxxxxxxxxxxxxxxxx
> +Description:	RW. Card reactive critical (I1) power limit in milliamperes.
> +
> +		Card reactive critical (I1) power limit in milliamperes is
> +		exposed for server products. The power controller will throttle
> +		the operating frequency if the power averaged over a window
> +		exceeds this limit.
> +
> +		Only supported for particular Intel xe graphics platforms.
> +
> diff --git a/drivers/gpu/drm/xe/xe_hwmon.c b/drivers/gpu/drm/xe/xe_hwmon.c
> index d66d633724a5..12298a0e8636 100644
> --- a/drivers/gpu/drm/xe/xe_hwmon.c
> +++ b/drivers/gpu/drm/xe/xe_hwmon.c
> @@ -12,6 +12,8 @@
>   #include "xe_gt.h"
>   #include "xe_hwmon.h"
>   #include "xe_mmio.h"
> +#include "xe_pcode.h"
> +#include "xe_pcode_api.h"
>   
>   enum xe_hwmon_reg {
>   	REG_PKG_RAPL_LIMIT,
> @@ -29,6 +31,7 @@ enum xe_hwmon_reg_operation {
>    * SF_* - scale factors for particular quantities according to hwmon spec.
>    */
>   #define SF_POWER	1000000		/* microwatts */
> +#define SF_CURR		1000		/* milliamperes */
>   
>   struct xe_hwmon {
>   	struct device *hwmon_dev;
> @@ -184,18 +187,43 @@ static int xe_hwmon_power_rated_max_read(struct xe_hwmon *hwmon, long *value)
>   }
>   
>   static const struct hwmon_channel_info *hwmon_info[] = {
> -	HWMON_CHANNEL_INFO(power, HWMON_P_MAX | HWMON_P_RATED_MAX),
> +	HWMON_CHANNEL_INFO(power, HWMON_P_MAX | HWMON_P_RATED_MAX | HWMON_P_CRIT),
> +	HWMON_CHANNEL_INFO(curr, HWMON_C_CRIT),
>   	NULL
>   };
>   
> +/* I1 is exposed as power_crit or as curr_crit depending on bit 31 */
> +static int xe_hwmon_pcode_read_i1(struct xe_gt *gt, u32 *uval)
> +{
> +	/* Avoid Illegal Subcommand error */
> +	if (gt_to_xe(gt)->info.platform == XE_DG2)
> +		return -ENXIO;
> +
> +	return xe_pcode_read(gt, PCODE_MBOX(PCODE_POWER_SETUP,
> +			     POWER_SETUP_SUBCOMMAND_READ_I1, 0),
> +			     uval, 0);
> +}
> +
> +static int xe_hwmon_pcode_write_i1(struct xe_gt *gt, u32 uval)
> +{
> +	return xe_pcode_write(gt, PCODE_MBOX(PCODE_POWER_SETUP,
> +			      POWER_SETUP_SUBCOMMAND_WRITE_I1, 0),
> +			      uval);
> +}
> +
>   static umode_t
>   xe_hwmon_power_is_visible(struct xe_hwmon *hwmon, u32 attr, int chan)
>   {
> +	u32 uval;
> +
>   	switch (attr) {
>   	case hwmon_power_max:
>   		return xe_hwmon_get_reg(hwmon, REG_PKG_RAPL_LIMIT) ? 0664 : 0;
>   	case hwmon_power_rated_max:
>   		return xe_hwmon_get_reg(hwmon, REG_PKG_POWER_SKU) ? 0444 : 0;
> +	case hwmon_power_crit:
> +		return (xe_hwmon_pcode_read_i1(hwmon->gt, &uval) ||
> +			!(uval & POWER_SETUP_I1_WATTS)) ? 0 : 0644;
>   	default:
>   		return 0;
>   	}
> @@ -204,11 +232,23 @@ xe_hwmon_power_is_visible(struct xe_hwmon *hwmon, u32 attr, int chan)
>   static int
>   xe_hwmon_power_read(struct xe_hwmon *hwmon, u32 attr, int chan, long *val)
>   {
> +	int ret;
> +	u32 uval;
> +
>   	switch (attr) {
>   	case hwmon_power_max:
>   		return xe_hwmon_power_max_read(hwmon, val);
>   	case hwmon_power_rated_max:
>   		return xe_hwmon_power_rated_max_read(hwmon, val);
> +	case hwmon_power_crit:
> +		ret = xe_hwmon_pcode_read_i1(hwmon->gt, &uval);
> +		if (ret)
> +			return ret;
> +		if (!(uval & POWER_SETUP_I1_WATTS))
> +			return -ENODEV;
> +		*val = mul_u64_u32_shr(REG_FIELD_GET(POWER_SETUP_I1_DATA_MASK, uval),
> +				       SF_POWER, POWER_SETUP_I1_SHIFT);
> +		return 0;
>   	default:
>   		return -EOPNOTSUPP;
>   	}
> @@ -217,9 +257,63 @@ xe_hwmon_power_read(struct xe_hwmon *hwmon, u32 attr, int chan, long *val)
>   static int
>   xe_hwmon_power_write(struct xe_hwmon *hwmon, u32 attr, int chan, long val)
>   {
> +	u32 uval;
> +
>   	switch (attr) {
>   	case hwmon_power_max:
>   		return xe_hwmon_power_max_write(hwmon, val);
> +	case hwmon_power_crit:
> +		uval = DIV_ROUND_CLOSEST_ULL(val << POWER_SETUP_I1_SHIFT, SF_POWER);
> +		return xe_hwmon_pcode_write_i1(hwmon->gt, uval);
> +	default:
> +		return -EOPNOTSUPP;
> +	}
> +}
> +
> +static umode_t
> +xe_hwmon_curr_is_visible(const struct xe_hwmon *hwmon, u32 attr)
> +{
> +	u32 uval;
> +
> +	switch (attr) {
> +	case hwmon_curr_crit:
> +		return (xe_hwmon_pcode_read_i1(hwmon->gt, &uval) ||
> +			(uval & POWER_SETUP_I1_WATTS)) ? 0 : 0644;
> +	default:
> +		return 0;
> +	}
> +}
> +
> +static int
> +xe_hwmon_curr_read(struct xe_hwmon *hwmon, u32 attr, long *val)
> +{
> +	int ret;
> +	u32 uval;
> +
> +	switch (attr) {
> +	case hwmon_curr_crit:
> +		ret = xe_hwmon_pcode_read_i1(hwmon->gt, &uval);
> +		if (ret)
> +			return ret;
> +		if (uval & POWER_SETUP_I1_WATTS)
> +			return -ENODEV;
> +		*val = mul_u64_u32_shr(REG_FIELD_GET(POWER_SETUP_I1_DATA_MASK, uval),
> +				       SF_CURR, POWER_SETUP_I1_SHIFT);
> +		return 0;
> +	default:
> +		return -EOPNOTSUPP;
> +	}
> +}
> +
> +static int
> +xe_hwmon_curr_write(struct xe_hwmon *hwmon, u32 attr, long val)
> +{
> +	u32 uval;
> +
> +	switch (attr) {
> +	case hwmon_curr_crit:
> +		uval = DIV_ROUND_CLOSEST_ULL(val << POWER_SETUP_I1_SHIFT, SF_CURR);
> +		return xe_hwmon_pcode_write_i1(hwmon->gt, uval);
>   	default:
>   		return -EOPNOTSUPP;
>   	}
> @@ -238,6 +332,9 @@ xe_hwmon_is_visible(const void *drvdata, enum hwmon_sensor_types type,
>   	case hwmon_power:
>   		ret = xe_hwmon_power_is_visible(hwmon, attr, channel);
>   		break;
> +	case hwmon_curr:
> +		ret = xe_hwmon_curr_is_visible(hwmon, attr);
> +		break;
>   	default:
>   		ret = 0;
>   		break;
> @@ -261,6 +358,9 @@ xe_hwmon_read(struct device *dev, enum hwmon_sensor_types type, u32 attr,
>   	case hwmon_power:
>   		ret = xe_hwmon_power_read(hwmon, attr, channel, val);
>   		break;
> +	case hwmon_curr:
> +		ret = xe_hwmon_curr_read(hwmon, attr, val);
> +		break;
>   	default:
>   		ret = -EOPNOTSUPP;
>   		break;
> @@ -284,6 +384,9 @@ xe_hwmon_write(struct device *dev, enum hwmon_sensor_types type, u32 attr,
>   	case hwmon_power:
>   		ret = xe_hwmon_power_write(hwmon, attr, channel, val);
>   		break;
> +	case hwmon_curr:
> +		ret = xe_hwmon_curr_write(hwmon, attr, val);
> +		break;
>   	default:
>   		ret = -EOPNOTSUPP;
>   		break;
> diff --git a/drivers/gpu/drm/xe/xe_pcode.h b/drivers/gpu/drm/xe/xe_pcode.h
> index 3b4aa8c1a3ba..08cb1d047cba 100644
> --- a/drivers/gpu/drm/xe/xe_pcode.h
> +++ b/drivers/gpu/drm/xe/xe_pcode.h
> @@ -22,4 +22,9 @@ int xe_pcode_write_timeout(struct xe_gt *gt, u32 mbox, u32 val,
>   int xe_pcode_request(struct xe_gt *gt, u32 mbox, u32 request,
>   		     u32 reply_mask, u32 reply, int timeout_ms);
>   
> +#define PCODE_MBOX(mbcmd, param1, param2)\
> +	(FIELD_PREP(PCODE_MB_COMMAND, mbcmd)\
> +	| FIELD_PREP(PCODE_MB_PARAM1, param1)\
> +	| FIELD_PREP(PCODE_MB_PARAM2, param2))
> +
>   #endif
> diff --git a/drivers/gpu/drm/xe/xe_pcode_api.h b/drivers/gpu/drm/xe/xe_pcode_api.h
> index 837ff7c71280..5935cfe30204 100644
> --- a/drivers/gpu/drm/xe/xe_pcode_api.h
> +++ b/drivers/gpu/drm/xe/xe_pcode_api.h
> @@ -35,6 +35,13 @@
>   #define     DGFX_GET_INIT_STATUS	0x0
>   #define     DGFX_INIT_STATUS_COMPLETE	0x1
>   
> +#define   PCODE_POWER_SETUP			0x7C
> +#define     POWER_SETUP_SUBCOMMAND_READ_I1	0x4
> +#define     POWER_SETUP_SUBCOMMAND_WRITE_I1	0x5
> +#define	    POWER_SETUP_I1_WATTS		REG_BIT(31)
> +#define	    POWER_SETUP_I1_SHIFT		6	/* 10.6 fixed point format */
> +#define	    POWER_SETUP_I1_DATA_MASK		REG_GENMASK(15, 0)
> +
>   struct pcode_err_decode {
>   	int errno;
>   	const char *str;